Protecting apron for charge at blast furnace top



PROTECTING APRON FOR CHARGE AT BLAST FURNACE TOP Nov. 21, 1961 KEIJI TSUJIHATA ET AL 3 Sheets-Sheet 1 Filed Dec.

FIG.

FIG.2

INVENTORS KEIJI TSUJ'HATA YASUHIRO SAWADA Y M, 6 04,

Nov. 21, 1961 KElJl TSUJIHATA ET AL PROTECTING APRON FOR CHARGE AT BLAST FURNACE TOP 3 Sheets-Sheet 2 Filed Dec.

FIG.4

INVENTORS KE IJI TSUJIHATA YASUHIRO SAWADA BY W,

Nov. 21, 1961 KEIJI TSUJIHATA ETAL 3,009,691

PROTECTING APRON FOR CHARGE AT BLAST FURNACE TOP Filed Dec. 14, 1959 3 Sheets-Sheet 3 INVENTORS Patented Nov. 21, 1961 3,009,691 PROTECTING APRON FOR CHARGE AT BLAST FURNACE TOP Keiji Tsujihata, Tobata City, and Yasuhiro Sawada, Kokura City, Japan, assignors to Yawata Iron & Steel Co., Ltd., Tokyo, Japan Filed Dec. 14, 1959, Ser. No. 859,200 Claims priority, application Japan Dec. 18, 1958 5 Claims. (Cl. 263-31) This invention relates to blast furnaces and more particularly to a metallic protecting apron for blast furnace charges at the top of the blast furnace shaft wall which has been subject to the impact and abrasive forces of the charges as they are dropped into the furnace.

According to the present invention, an improved apron or guard for the blast furnace charges which has been subject to an excessive damage and wear whenever the charges are dropped into the furnace is made of elastic construction in order to minimize the impact of the charges, also provided with an adjustable support rod by which a pendent angle of the apron or guard can be adjusted witha view to changing the distribution of the charges in the furnace, and further provided with a plurality of shelves for accommodating the charges in which they are piled up for the purpose of decreasing the im pact and abrasion imparted directly to the apron or guard.

The apron or guard provided at the top of the shaft wall of prior art is of rigid stationary type and consists of several metallic aprons held in place by bricks so that it' is subject directly to the impact and abrasive forces of 'the materials to be charged into the blast furnace with the result that it is exceedingly deteriorated because it is held in place by bricks. Accordingly, the life of a blast furnace has been considerably shortened due to the damage resulting from the excessive wear of the top thereof. To overcome the above disadvantage, the present invention contemplates the provision of a single metallic apron or guard instead of a conventional rigid stationary one consisting of several plates, said single metallic apron J is hung by a pin at its top, and supported by an adjustable support rod at its bottom, one end of the adjustable support rodisheld by an elastic element,. for example, a

" the piled charges willfall in with the impact and abrasive forces of the charges admitted into the furnace through the charging bell. By this construction of the metallic apron, the charges admitted through the charging bell does not encounter the apron directly, but the piled charges in the shelves to be splashed or dumped into the "furnace along the piled charges with the result that the wear and abrasion of the apron is considerably reduced.

Accordingly, it is an object of the invention to provide an increased life of the blast furnace by hanging down a metallic apron for the charges at its upper part at the top of the blast furnace shaft wall, and mounting the apron by means of an adjustable rod at its bottom, thereby the impact and abrasive forces of the materials to be charged are resisted in order to prevent the wear and damage of the top wall thereof.

It is another object of the invention to increase a pro duction rate of the blast furnace by the provision of an elastic construction of the apron at the top wall of the blast furnace in which the upper part of the apron is hung down at the furnace wall by a pin and the lower part is held by an adjustable rod so that the apron can move back and forth so as to change the distribution of ore, coke and other materials to be dropped into the furnace at will and improve the reduction of ore therein.

It is another object of the invention to provide an improved metallic apron by hanging it down by a pin at its upper part from the furnace wall, mounting it with an adjustable rod at its lower part, and providing a plurality of shelves at the upper part thereof to accommodate a'pile of materials to be charged into the furnace so as to have the piled materials encounter the impact and abrasion of a fresh charge in order to protect the apron and prolong the life thereof.

It is still another object of the invention to provide an improved apron for the charges having a prolonged life by providing a relatively simple means at the top wall of the blast furnace shaft which has been subject to excessive wear and abrasion.

Other objects and advantages of this invention will be apparent from a consideration of the following descrip- 'tion of a preferred embodiment of the invention and the accompanying drawings in which:

FIG. 1 is a sectional view showing a charge apron apparatus of the invention installed at the top wall of the blast furnace shaft.

FIG. 2 is a plan view of a part of the apparatus of FIG. 1.

FIG. 3 is a sectional view of the charge apron apparatus of the invention.

FIG. 4 is a plan view of a part of the apparatus of FIG. 3.

FIG. 5 is a sectional view showing the upper part of the apparatus provided with a plurality of shelves.

FIG. 6 is a sectional view showing the apparatus of FIG. 5 piled with the material charge.

It is to be understood that the present invention will not be limited to the following preferred embodiment, which will be described in connection with the drawings.

As shown in FIGS. -1-4 inclusive, the apparatus of the invention consists of acharge apron body 6,'the upper end of which is pivotally mounted at the furnace wall through a bracket 9 for the apron by a pin 14, and the lower end of which is also pivotally and freely mounted at a joint recess 5 by the end 4 of an adjustable support rod 8. This free joint mechanism is adopted because it ther it does not affect the above angle of the apron apparatus when adjusting the adjustable rod 8, although the joint is worn out. The adjustable rod 8 is supported by an elasticspring 7 as shown in FIG. 2. This elastic spring device consists of an outer cylinder 11 attached to the furnace mantle 17, an inner cylinder 13 which holds a spring 7, a gas-tight chamber 10 to prevent gas 1eak,and an adjustable cap' 12 for the adjustable rod 8 carrying the charge apron apparatus. It is to be understood, however, thatnan elastic mounting of the adjustable rod 8 to the furnace wall will not be limited to the above embodiment of the invention. In reference to a skirt 21 of the charge apron body 6 it is not always an indispensable part of the apparatus, but the apparatus can dispense with it as desired.

The function of the apron apparatus of the invention will be described in detail in connection with FIGS. 1-4. The charges 2 dumped into the charging bell 1 as shown in FIGS. 1-2 are dropped into the furnace simultaneously towards the apron apparatus 6 as the charging bell 1 is lowered to a position illustrated in a dot-and-dash line. When the charges 2 encounter the apron 6, the greatest impact of the charges is taken up by the adjustable support rod 8, because the apron is pivotally hung down by a pin 14 at its top through a bracket 9 from the furnace top wall, and also supported by the adjustable support rod 8 at its bottom. Furthermore, the adjustable support rod 8 is held by an elastic spring 7, which results in taking up the greatest impact by means of this spring 7. In this way and by this apparatus, the charge apron installed at the top of the blast furnace shaft wall is protected from damage and abrasion.

The adjustable support rod 8 held by the spring can be adjusted by screwing an adjusting cap 12 tightly or loosely as desired. When the adjusting cap 12 is screwed up tightly, the charge apron 6 is projected towards the center of the furnace 15 as shown in a dot-and-dash line 16 while, conversely, the charge apron 6 is drawn towards the furnace wall as the cap is screwed down loosely. By the operation and function of this device, when the charge apron 6 is projected to assume a position 16 as illustrated in a dot-and-dash line, the charges are dropped into the center of the furnace 15 more abundantly than anywhere else depending upon the change of a reflecting angle while, on the other hand, when the charge apron 6 is drawn to the furnace wall, the charges are dumped into the wall side of the furnace 15 more plentifully than the center.

In reference to the charge apron provided with a plurality of shelves at its upper part as shown in FIGS. -6, the charge apron is provided with a shelf 19 and 22 constructed so as to accommodate a chamber 20 and 21 for holding a pile of charges therein which forms a protecting layer consisting of charges. As shown in FIG. 6, the shelf 19 is made of plate, but may be made of screen, and a plurality of shelves is provided.

By the above construction of the charge apron 6 provided with shelves, the charge material serves as a protecting layer or lining for the furnace top wall, since the chambers for holding the charge are always filled with it so that the protecting layer or lining 23 consisting of the charge material is maintained over the top wall.

Referring to the function of shelves, the blast furnace charge 2 dumped into the charging bell 1 as shown in FIG. 1 is dropped into the furnace towards the apron 6 as the charging bell 1 is lowered down to the position 3 illustrated in a dot-and-dash line. As shown in FIG. 6, the thus dropped and charged material 2 falls in with the material 23 already piled in the chamber 20 and 21 installed in the shelves of the apron 6 to be splashed or dropped into the furnace therealong. In other words, the charged material does not encounter directly the apron 6,

but the piled material therein, hence the apron 6 is pre- 1 ventedfrom the impact and abrasive forces of the charge.

As the charge apron 6 is suspended by the pin 14 at its top through the bracket 9 and held at its bottom by the adjustable support rod 8, the greatest impact of the charge to the apron is almost taken up by the support rod 8 just the same as there is no charge piled up in the chamber of the apron, and further, as the adjustable support rod 8 is held by the elastic spring 7, the shock is more and more absorbed effectively.

As fully described hereinbefore in connection with FIGS. 1-6, the apron apparatus of the invention can prevent the excessive wear and abrasion of the charge apron of prior art, one of the greatest causes to weaken the durability of the blast furnace, and at the same time, the apron apparatus of the invention can increase not only the production rate of the blast furnace, but also the life thereof considerably, since the distribution of the charge material in the furnace can be easily controlled as desired, a more uniform reduction of ores can be attained, a stable operation of the furnace can be obtained, and the coke ratio can be decreased.

Numerous variations and modifications will suggest themselves to those skilled in the art and we therefore do not intend to limit ourselves otherwise than as set forth in the claims which follow.

We claim:

1. In a furnace of the type having a refractory wall extending to a point adjacent to the top thereof and having a charging device on the top of the furnace for charging materials into the furnace and directing them against the top of the refractory wall, that improvement comprising a plurality of aprons pivotally suspended around the inside periphery of the top of the furnace for pivotal movement toward and away from the center of the furnace, said aprons depending to a point at least below the level of the top of the refractory wall, and resilient means engaging with said aprons for normally holding said aprons in position and permitting said aprons to move under the impact of material against them, said aprons being pivotable from a first position in which they are substantially in alignment with the inner periphery of said refractory wall and in the path between said charging means and the top of said refractory wall and a position in which the aprons are slanted downwardly and inwardly toward the center of the furnace.

2. The improvement as claimed in claim 1 in which the pivotal suspension of each of said aprons from said furnace comprises a bracket on the top portion of said furnace having a pair of upwardly opening notches therein, and a pin on said apron resting on said notches for pivotal movement therein, and said resilient means for each apron comprises a rod in rotatable engagement with said apron on the depending portion thereof and extending outwardly of said furnace through the side thereof, spring means between said rod and said furnace, and means for adjusting said spring means relative to said furnace to change the position of said apron.

3. The improvement as claimed in claim 1 in which each of said aprons has a plurality of pockets in the upper portion thereof, each of said pockets opening out of said apron in an upward and outward direction toward said charging means, whereby said pockets are filled with charged material and expose a surface of charged material to the charging device at the upper portion of the apron.

4. The improvement as claimed in claim 3 in which the walls of said pockets are of solid plate material.

5. The improvement as claimed in claim 3 in which the walls of said pockets are of screen.

References Cited in the file of this patent UNITED STATES PATENTS 1,564,813 Babendreir Dec. 8, 1925 1,835,225 Knoringer et a1 Dec. 8, 1931 2,693,886 Grindle Nov. 9, 1954 2,710,747 Shea June 14, 1955 FOREIGN PATENTS 416,493 Germany July 16, 1925 559,823 Germany Sept. 24, 1932 864,880 Germany Jan. 29, 1953 

